Circulating Tumor DNA Linked to Post-Treatment Relapse in Breast Cancer

The presence of circulating tumor DNA in breast cancer patients following their initial treatment with chemotherapy may be useful in identifying those likely to relapse, according to a new study appearing in JCO Precision Oncology. While standard treatments are effective for early-stage breast cancer, around 30 percent of patients experience recurrence in the first 10 years after surgery. Recent research has suggested that ctDNA detection after neoadjuvant therapy in early-stage breast cancer patients can identify relapse much sooner than imaging, though this hypothesis has yet to be tested. To do so, a group led by scientists from the Institut Jules Bordet and Université Libre in Brussels analyzed 157 plasma samples from 44 patients — taken before and after chemotherapy, as well as before surgery and serially after surgery — using Natera's Signatera ctDNA assay. After adjusting for pathologic complete response, ctDNA detection before surgery and at the last follow-up blood draw was associated with shorter relapse-free survival. The findings, the study's authors write, are consistent with observations that ctDNA is more often detected in aggressive tumors with higher tumor proliferation and support additional studies into the clinical utility of ctDNA monitoring.